Swivel-caster



i. L. CHESNUTT,

SWIVEL CASTERL APV'IICATION FILED APRV3O.I921.

Patented Oct, l1, 192i nire yil" .E d

@FIL

SWVEL-CASTER.

recaer-4i.

Specification of Letters Patent.

Patented @on M, 1921.,

Application filed April 30, 1921. Serial No. 465,837.

To aZZ whom t may concer/L.'

Be it known that l, JOHN lioUctnN Ctres- NUTT, a citizen oi the United States of America, and resident of Long Beach, Los Angeles county, California, have invented a new and useful Swivel-Caster, of which the following is a Speciication.

The object of this invention is to provide an improved construction for a swivel caster especially adapted tor use on household and ofiice furniture.

A further object of this invention is to provide an improved swivel caster havingI anti-friction connections between the sta tionary and swiveling parts possessing the highest swivelinfr eliiciency, thereby securing ease in operation, longer lite of parts. less strain on the load object and less wear on the floors traversed.

A further object of this invention is to produce a swivel caster of exceedingly simple construction, which is economical to manufacture and not apt to get out of order.

A further object of this invention is to provide an improved swivel caster so arranged as to provide a large diameter for the race of balls taking lateral strain and to altord an anti-friction retaining means resulting in decreased leverage, less strain and friction and consequent wear and breakage, as well as increasing the swiveling etticiency.

A further object ot' this invention is to provide improved means for securing the caster to a load object.

With these and other objects in view, my invention consists in the construction, arrangement and combination of elements hereinafter set forth, pointed out in my claims and illustrated by the accompanying drawing, in which- Figure 1 is a vertlcal section illustrating the swiveling features of my improved caster. Fig. 2 is a transverse section on the line 2-2 ot Fig. 1. Fig. 3 is ay iront view of the lower portion of the device, the wheel being shown in section. Fig. 1- is a vert-ical section of the swiveling parts, showingn a modiied construction.

in the construction of the device as shown a wheel 10 oid any suitable construction is journaled for rotation in a wheel yoke formed with spaced parallel wings 1l., 12 formed on and extending downwardly trom cylindrical body portion lil. The wings 11, l2 taper coward their lower ends anc!v project rearwardly of the vertical axis of the body 13, and the wheels axis of rotation is set to the rear of the said vertical axis. The wheel 10 preferably is of suitable anti-friction construction, one form ot which 1s shown in Fig. 3. rThe cylindrical body 13 ot' the yoke is formed at its top with an annular cover member 14 having a relatively large opening 15 ot circular form concentric with the vertical axis of the device. A load .bearing device is provided and extends within the body portion of the wheel yoke, on which load hearin device said wheel yoke is adapted to swivel or rotate. This load device comprises primarily a cylindrical shell 16 extending through the central aperture 15 of the top of wheel yoke and toi-med at its lower end with an outwardly and downwardly extending peripheral flange 17 projecting beneath the top ot the wheel yoke and spaced from the top and body of said wheel yoke. The peripheral flange 17 is formed on its outer tace and near its periphery with a concaved or groove-d surface forming a ball race 18 within which is mounted an annular row 19 of bearing halls, which also contact the body and top of the wheel yoke. It is the function of the balls 19 to receive lateral pressure and strain only, which strain is exerted upon them on oblique or diagonal lines of approximately fortyfive degrees to the perpendicular. The cylindrical shell l-fextends a short distance above the top 14 of the wheel yoke and is formed with an inwardly projecting flange or shoulder 20 of annular form. As shown in Fig. 1 the load bearing device extends upwardly a considerable distance above the shoulder or flange QOand is tapered, forming a. hollow stem 21, closed at its top except for a screw hole 22 formedcentrally therein. The tapered stem 21 is adapted to be received within a socket or bore of an object to he supported, such as a leg or other portion ot an article et furniture, and to be secured therein by any desired means, as for instance a screw extending upwardly through the hole 22 and seated in said object. lt is to be understood, however, that the stem 21 may be 'termed solid and that the screw may be formed on and project upwardly troni its upper end; or other suitable securing means majv he employed for retaininn' the caster in a load object, one ot which is hereinafter more particularly described.

A. cupped washer 23 is mounted over the stem 21 and tits snugly the lower end therea i of, resting rigidly on the flange or shoulder 20.' The washer 2? is cupped, pressed -or curved downwardly at its outer periphery to form a raceway 2d and retaining means for an annular row 25 oi bearing balls rest ing on the annular plate or top 14 of the wheel yoke. The load object to be supported is adapted to rest on the washer 23, which would extend circumfer'entially of the hole or socket in said object when the connection above referred to is employed. lhe washer 23 in `turn rests on the balls 25, which are designed to receivev vertical pressure, or pressure of the load only, and no' lateral strains, as there is a clearance between said balls and the adjacent sides of the shell 16, or in other words said balls have somelateral play or freedom ot movement.

It will be noted that the manner of con necting the swiveling member to thev sta tionary member, and oi forming. the ball races, provides raceways of relatively large diameter for both rows of ybearing balls, which affords large anti-friction surfaces re sulting in decreased leverage on the device under strain, lessons strain, friction, wear, and breakage 'and gives increased swiveling eiciency.

Also that the provision that each row of bearing balls receives pressure in one direction only, either lateral or vertical, adds largely to the eiiciency and life of the device by decreasing wear on the balls and races, as theV balls have no tendency to rotate on more than one axis simultaneously.

In Fig. d I have illustrated another form of load bearing devicein which the stem 2l is omitted and substituted by a horizontal plate 26, of any desired form and shape, a

ortion only being shown. The plate 26 is ormed with a central hole fitting the upper end of a neck 27 formed on the load bearing member above the flange or shoulder 20, said plate resting on the cupped washer 23 and eing held in place by an outturned dange '2.8 on the upper end oi said neck. The plate 26 is adapted to be attached tothe Hat under surface olY a load object in any suitable manner. i

The shoulder, flange or offset 20 spaces the disk or washer 23 correctl relative to the top of the wheel yoke, al owing space for proper swiveling and for both rows oi balls'q The antiiriction connecting means between the stationary and swiveling parts provides a raceway in which the balls extend outside the vertical plane passing through the laxis of the wheel l0, thus decreasing leverage, strain, friction, wear and breakage ofthe parte.

l cl as my invention@ f l.. A. swivel caster, comprising a wheel yoke and wheel pivoted therein,` said wheel yoke being formed with a cylindrical body and an annular plate thereon, a load bearing member having a cylindrical shell projecting through the annular plate of said yoke and terminating1 in an outwardl vand downwardly extending Vflange, sai ilange bein yfornnad on its outer face with a concave raceway, bearing balls mounted in said raceway and in contact with saidwheelyoke and adapted to receive lateral pressure only, said shell being formed at its upper end with a dange or shoulder and also provided with means for attaching to a load object, a cupped disk or washer supported rigidly on the shoulder or angc and formed with an internal raceway, and bearing balls in said raceway and rting on the annular plate of the wheel yoke, the last-named balls being' adapted to receiveV vertical pressure onl 2. A swivel caster, comprising a w eel yoke and wheel pivoted therein, said wheel yoke being formed with a cylindrical body and with an annular plate on the upper end thereof, a load bearing member including a cylindrical shell extending through the annular plate ot thewheel yoke, said shell terminating in a downwardly and outwardly projecting flange extending beneath the plate of the wheel yoke, said flange being formed peripherally with. an external raceway, an annular row of balls kmounted in said raceway and contacting the walls of said shell and annular plate, said shell being formed at its upper end with a angeor shoulder, a hollow stem integrally formed with said shell and extending upwardly from said ange or shoulder, a cupped washer arranged concentrically of said stem and supptnrtedv rigidly on said ange or shoulder, said stem and cupped washer adapted to support a load object, and anannular row of bearing balls mounted within said cupped washertand resting on the annular plate of the lwheel yoke, Said lastnamed balls having a :freedom of movement latlerally and receiving downward pressure on Sly ln a swivel caster, a wheel oke and wheel pivoted therein, said yo e being formed with a flat annular top member, and a load bearing member extending within said oke and formed with an external shoul er, a cupped disk mounted on said shoulder, and bearing balls within said `cupped disk resting on said annular top member ci the yoke. o Signed at Des' Moines, in the county of Polk and State of lowa, this 8" vday of April, M2?.

@ll-lhl LOUClEN CHESNT. 

